Device for cooling and/or heating an electric vehicle battery

Abstract

A device for use in a circuit for cooling and/or heating a motor vehicle battery, including: an outer casing of a composition including: from 20% to 65% by weight of reinforcing fibers, which do not have thermal conduction properties, the balance being a matrix including at least one polyamide and an inner casing positioned facing the battery and intended to be in contact with a coolant of a composition including: from 5% to 65% by weight of reinforcing fibers, from 10% to 20% by weight of at least one thermally conductive component, when the reinforcing fibers used are not thermally conductive, at least one fire retardant, and the balance being a matrix including at least one polyamide chosen from semiaromatic polyamides and polyamides, a heat transfer fluid inlet; and a heat transfer fluid outlet, the device delimiting a battery cooling and/or heating volume.

The invention claimed is: 
     
       1. A device for use in a cooling and/or heating circuit of an electric or hybrid motor vehicle battery, comprising:
 an outer envelope consisting of a first composition comprising:
 20 to 65% by weight of reinforcing fibers which do not have heat-conducting properties, in relation to the total weight of the first composition, 
 the complement of the first composition being a matrix comprising mostly at least one polyamide such that the first composition does not include any reinforcing fibers having heat-conducting properties or other thermally conductive component, and 
 
 an inner envelope disposed opposite the battery and intended to be in contact with a cooling fluid, the inner envelope consisting of a second composition comprising:
 5 to 65% by weight of reinforcing fibers in relation to the total weight of the second composition, wherein the reinforcing fibers of the second composition are either reinforcing fibers which do not have heat-conducting properties or reinforcing fibers which have heat-conducting properties, 
 if the reinforcing fibers of the second composition do not have heat-conducting properties, 10 to 20% by weight of at least one thermally conductive component, in relation to the total weight of the second composition, 
 at least one flame retardant, and 
 the complement of the second composition being a matrix comprising mostly at least one polyamide chosen from semi-aromatic polyamides and polyamides consisting of units having an average number of carbon atoms per nitrogen atom ranging from 7 to 10, 
 
 a heat transfer fluid inlet; and 
 a heat transfer fluid outlet, 
 the device delimiting a cooling and/or heating volume of the battery. 
 
     
     
       2. The device according to  claim 1 , wherein the outer envelope comprises a polyamide matrix comprising at least one polyamide chosen from semi-aromatic polyamides and polyamides consisting of units having an average number of carbon atoms per nitrogen atom ranging from 9 to 18. 
     
     
       3. The device according to  claim 1 , wherein the outer envelope comprises a polyamide matrix comprising at least one polyamide selected from PA612, PA1010, PA10T, PA10T/1010, PA11, PA12, PA11/10T, PA12/10T, PA 1012, PA 618, PA 12T, PA 1010/1012, PA BACT/6T, PA BACT/10T, PA BACT/12T, PA MPMDT/6T, PA MPMDT/10T, PA MPMDT/12T, PA MXDT/6T, PA MXDT/10T, PA MXDT/12T, PA 11/BACT/6T, PA 11/BACT/10T, PA 11/BACT/12T, PA 11/MPMDT/6T, PA 11/MPMDT/10T, PA 11/MPMDT/12T, PA 11/MXDT/6T, PA 11/MXDT/10T, PA 11/MXDT/12T, and mixture thereof. 
     
     
       4. The device according to  claim 1 , wherein the inner envelope comprises a polyamide matrix comprising at least one polyamide selected from PA610, PA410, PA412, PA612, PA1010, PA6T, PA6I, PA9T, PA10T, PA6T/61, PA6T/10T, PA6T/1010, PA10T/1010, and mixture thereof. 
     
     
       5. The device according to  claim 1 , wherein the reinforcing fibers not having heat-conducting properties are chosen from glass fibers, basalt fibers and aramid fibers. 
     
     
       6. The device according to  claim 1 , wherein the reinforcing fibers having heat-conducting properties are selected from carbon, carbon fibers, carbon black, carbon nanotubes, expanded graphite, aluminum nitride and boron nitride. 
     
     
       7. The device according to  claim 1 , wherein the ratio of the thermal conductivity (λ) of the inner envelope to the thermal conductivity (λ) of the outer envelope is at least greater than 1.5. 
     
     
       8. The device according to  claim 1 , wherein the flame retardant is a metal salt selected from a metal salt of phosphinic acid, a metal salt of diphosphinic acid, a polymer containing at least one metal salt of phosphinic acid, a polymer containing at least one metal salt of diphosphinic acid; red phosphorus, an antimony oxide, a zinc oxide, an iron oxide, a magnesium oxide, metal borates, melamine cyanurates, siliconated or fluoridated type non-drip agents, and mixture thereof. 
     
     
       9. The device according to  claim 1 , wherein when the battery comprises a plurality of adjacent cell packs, then the inner envelope encapsulates the assembly of cells by complementarity of shape. 
     
     
       10. The device according to  claim 1 , wherein the inner envelope and/or the outer envelope is/are coated on the inside and/or the outside with a layer having a low water permeability. 
     
     
       11. The device according to  claim 1 , wherein the first and second compositions are different. 
     
     
       12. A system for cooling and/or heating a battery of an electric or hybrid motor vehicle, the system comprising: a cooling and/or heating circuit, a refrigerant selected from the compounds that are hydrocarbons, hydrofluorocarbons, ethers, hydrofluoroethers, halocarbons, CO2, NH3, SO2 and fluoroolefins, and the device of  claim 1 . 
     
     
       13. The system of  claim 12 , wherein the refrigerant is selected from CO2, haloalkanes, haloalkenes, fluoropropenes, fluoropropanes and fluoroethanes, and mixtures thereof. 
     
     
       14. The system of  claim 13 , wherein the refrigerant is chosen that the heat transfer fluid is a refrigerant selected from 1,3,3,3-tetrafluoropropene (1234ze), 2,3,3,3-tetrafluoropropene (1234yf), difluoromethane, 1-chloro-3,3,3,3-tetrafluoropropene (HCFO-1233zd), 1-chloro-2,3,3,3-tetrafluoropropene (HCFO-1224 yd), and 1,1,1,4,4,4-hexafluorobut-2-ene (HFO-1336mzz). 
     
     
       15. The system of  claim 12 , wherein the refrigerant fluid contains a lubricant. 
     
     
       16. A cooling and/or heating circuit for an electric or hybrid motor vehicle battery, comprising a main circulation loop for a heat transfer fluid provided with means intended for the circulation of the heat transfer fluid in the main circulation loop, wherein the main circulation loop is connected to a reversible heat pump and the device as defined in  claim 1 .